246 research outputs found
Modulating membrane shape and mechanics of minimal cells by light: area increase, softening and interleaflet coupling of membrane models doped with azobenzene-lipid photoswitches
Light can effectively interrogate biological systems providing control over complex cellular processes. Particularly advantageous features of photo-induced processes are reversibility, physiological compatibility, and spatiotemporal precision. Understanding the underlying biophysics of light-triggered changes in bio-systems is crucial for cell viability and optimizing clinical applications of photo-induced processes in biotechnology, optogenetics and photopharmacology. Employing membranes doped with the photolipid azobenzene-phosphatidylcholine (azo-PC), we provide a holistic picture of light-triggered changes in membrane morphology, mechanics and dynamics. We combine microscopy of giant vesicles as minimal cell models, Langmuir monolayers, and molecular dynamics simulations. We employ giant vesicle elelctrodeformation as a facile and accurate approach to quantify the magnitude, reversibility and kinetics of light-induced area expansion/shrinkage as a result of azo-PC photoisomerization and content. Area increase as high as ~25% and a 10-fold decrease in the membrane bending rigidity is observed upon trans-to-cis azo-PC isomerization. These results are in excellent agreement with simulations data and monolayers. Simulations also show that trans-to-cis isomerization of azo-PC decreases the membrane leaflet coupling. We demonstrate that light can be used to finely manipulate the shape and mechanics of photolipid-doped minimal cell models and liposomal drug carriers, thus, presenting a promising therapeutic alternative for the repair of cellular disorders.Competing Interest StatementThe authors have declared no competing interest
Assessing membrane material properties from the response of giant unilamellar vesicles to electric fields
Knowledge of the material properties of membranes is crucial to understanding cell viability and physiology. A number of methods have been developed to probe membranes in vitro, utilizing the response of minimal biomimetic membrane models to an external perturbation. In this review, we focus on techniques employing giant unilamellar vesicles (GUVs), model membrane systems, often referred to as minimal artificial cells because of the potential they offer to mimick certain cellular features. When exposed to electric fields, GUV deformation, dynamic response and poration can be used to deduce properties such as bending rigidity, pore edge tension, membrane capacitance, surface shear viscosity, excess area and membrane stability. We present a succinct overview of these techniques, which require only simple instrumentation, available in many labs, as well as reasonably facile experimental implementation and analysis.
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The probable evidence of leprosy in a male individual unearthed in medieval Armenia (Angeghakot)
The objective of this study is to present the paleopathological lesions relevant to the discussion of the differential diagnosis of leprosy. Macroscopic, histological and X-ray observation of the bones and scrutiny of lesions according to the paleopathological literature allowed the identification of a probable case of leprosy in an adult male from Angeghakot (Early Middle Age, skeleton 4). The skeleton of a male (50–55 years) revealed several bony changes indicative of leprosy with clear rhino-maxillary syndrome. There is a scarcity of information in the osteoarchaeological literature of leprosy in ancient Armenia. The significance of this case is that it adds to an understanding of the history of the disease in Armenia and to the data set necessary to understand the epidemiological dynamics in the South Caucasus during the Early Middle Ages
Test Educational Materials in Pdf Format Development for Interactive Learning
Рассмотрен автоматизированный способ формирования интерактивных заданий с применением системы LuaLaTeX для самостоятельной проработки и закрепления материала обучающимися. Предлагаемый подход позволяет синтезировать задания, отличающиеся порядком вопросов и вариантов ответов из заданного перечня для одного исходного документа. Результат работы может быть применен в различных системах управления обучением.Forming interactive tasks automated method using the LuaLaTeX system for independent study and material consolidation by students is considered. The proposed approach allows you to synthesize tasks that differ in the questions and answers order from a given list from one source document. The result of the work can be applied in various learning management systems
АКТУАЛИЗАЦИЯ МЕТОДИКИ РАСЧЕТА ФАКТИЧЕСКОГО ПОКАЗАТЕЛЯ НАДЕЖНОСТИ ВЫЛЕТОВ ГРАЖДАНСКИХ ВОЗДУШНЫХ СУДОВ
Dispatch reliability – is one of the key criteria of aircraft technical operation process efficiency which reflects economic efficiency of airline activity. The higher the operational reliability, the better the level of aircraft operation in airline, the higher maintenance quality and safety policy is more effective. Due to the lack of unified procedure of dispatch reliability control both for aircraft manufacturers and Russian Federation aircraft operators and based on international experience it was concluded that there is a need for dispatch reliability specification by introducing a number of parameters, definitions and development, thereby the unified updated methodic of calculation. In this work six basic and three auxiliary parameters are introduced, the following terms and definitions are established: dispatch reliability, operational reliability, ground operational interruptions, operational interruptions, in-flight interruptions. A unified actualized methodic of dispatch reliability and operational reliability calculation is developed, which is reasonable and more accurate. Since the aircraft dispatch reliability includes the notion of Regularity and Punctuality, definitions and criteria calculation are given. The detailed example of criteria calculation is shown: dispatch reliability, dispatch regularity, flight punctuality, operational reliability, flight delays for a hundred landings, aircraft changes for a hundred landings, flight cancellations for a hundred landings.Надежность вылетов (далее – регулярность вылетов) – это один из ключевых критериев эффективности процесса технической эксплуатации воздушных судов, отражающий экономическую эффективность функционирования авиакомпании. Чем выше показатель эксплуатационной надежности выполнения рейсов, тем лучше авиакомпания справляется с эксплуатацией воздушных судов, тем выше качество обслуживания самолетов и эффективнее политика безопасности. В связи с отсутствием единого порядка учета регулярности вылетов воздушных судов как у предприятий – изготовителей воздушных судов, так и у эксплуатирующих воздушные суда авиакомпаний Российской Федерации и основании международного опыта, в работе сделан вывод о необходимости детализации расчета регулярности вылетов путем введения ряда параметров, определений и разработки тем самым единой актуализированной методики расчета. В данной работе введены шесть основных и три вспомогательных параметра, приняты следующие термины и определения: регулярность вылетов; эксплуатационная надежность; наземные сбои в эксплуатации; эксплуатационные прерывания; сбои, произошедшие в полете. Разработана актуализированная методика расчета регулярности вылетов и эксплуатационной надежности выполнения рейсов, которая является разумной и имеет более высокую точность. Поскольку регулярность вылетов воздушных судов включает понятие регулярности отправлений ВС (Regularity) и пунктуальности выполнения рейсов (Punctuality), даны определения и представлен расчет показателей для данных понятий. Детально показан пример расчета показателей: регулярности вылетов, регулярности отправлений, пунктуальности выполнений рейсов, эксплуатационной надежности выполнения рейсов, задержки рейсов на сто посадок, замены воздушных судов на сто посадок, отмены рейсов на сто посадок
КОМПЛЕКСНАЯ ТЕХНОЛОГИЯ ПОВЫШЕНИЯ ЭФФЕКТИВНОСТИ ПРОЦЕССА ТЕХНИЧЕСКОЙ ЭКСПЛУАТАЦИИ ВОЗДУШНЫХ СУДОВ
In the conditions of contemporary world market, the maintenance process to keep the required level of aircraft serviceability in airlines should be economically efficient in relation to labour, time and material expenses. The solution of the problem can be achieved by planning and managing the activity of airlines with the aim to improve the efficiency of civil aircraft maintenance process. Planning and implementation of activities for process improvement of aircraft maintenance efficiency in particular such factors as aircraft (A/C) reliability and safety, flight regularity and A/C timewise operation efficiency, A/C intensities and economy require collaboration and interaction of developer, manufacturer and operator. This work proves the need to develop the planning and performance technology of actions related to the airlines activity allowing step by step according to developer, manufacturer and operator activities to establish the cooperation and influence on aircraft serviceability, thereby increasing the maintenance process by all possible managing actions. The complex technology to improve the efficiency of aircraft maintenance process including activities on “A/C Reliability”, “Technology”, “Personnel”, “Equipment”, “Materials” has been developed with the aim to increase the A/C fleet serviceability level. The complex technology is represented as a route technology with brief description of destinations in the route chart with input/output indications at each stage.The advantages of complex technology application are shown in the example of improving one of the efficiency measures in aircraft maintenance process.В условиях современного мирового рынка процесс технической эксплуатации для поддержания требуемого уровня исправности парка воздушных судов в авиакомпаниях должен быть экономически выгодным в отношении трудовых, временных и материальных затрат. Решение данной задачи может быть достигнуто путем планирования и управления деятельностью авиапредприятий с целью повышения эффективности процесса технической эксплуатации воздушных судов гражданской авиации. Планирование и осуществление мероприятий, связанных с деятельностью авиапредприятий по улучшению показателей безотказности авиационной техники, безопасности и регулярности полетов, интенсивности использования воздушных судов и экономичности их процесса технической эксплуатации, требует организации совместной работы и взаимодействия разработчика, изготовителя и эксплуатанта воздушных судов. В данной статье обоснована необходимость в разработке технологии планирования и осуществления мероприятий, связанных с деятельностью авиапредприятий, позволяю- щей поэтапно по направлениям деятельности разработчика, изготовителя и эксплуатанта воздушных судов установить взаимосвязь и влияние на уровень исправности парка, тем самым повышая эффективность процесса технической эксплуатации путем всех возможных управляющих воздействий. Разработана комплексная технология повышения эффективности процесса технической эксплуатации воздушных судов, включающая мероприятия по направлениям «Надёжность воздушного судна», «Технология», «Персонал», «Оборудование», «Материалы», с целью повышения уровня исправности парка ВС. Комплексная технология представлена в виде маршрутной технологии с сокращенным описанием комплекса мероприятий по направлениям в маршрутной карте, с указанием входов и выходов на каждом этапе. Показаны преимущества применения комплексной технологии на примере улучшения одного из целевых показателей эффективности процесса технической эксплуатации воздушных судов.
Построение математической модели процессов технической эксплуатации авиационной техники как замкнутой системы массового обслуживания
A mathematical model of the processes of maintenance of aircraft engineering as a closed service system shoving their probability-statistic characteristics is constructed.Построена математическая модель процессов технической эксплуатации (ПТЭ) авиационной техники (АТ) как замкнутой системы массового обслуживания (СМО), отражающая их вероятностно-статистические характеристики
Think globally, measure locally: The MIREN standardized protocol for monitoring plant species distributions along elevation gradients
Climate change and other global change drivers threaten plant diversity in mountains worldwide. A widely documented response to such environmental modifications is for plant species to change their elevational ranges. Range shifts are often idiosyncratic and difficult to generalize, partly due to variation in sampling methods. There is thus a need for a standardized monitoring strategy that can be applied across mountain regions to assess distribution changes and community turnover of native and non-native plant species over space and time. Here, we present a conceptually intuitive and standardized protocol developed by the Mountain Invasion Research Network (MIREN) to systematically quantify global patterns of native and non-native species distributions along elevation gradients and shifts arising from interactive effects of climate change and human disturbance. Usually repeated every five years, surveys consist of 20 sample sites located at equal elevation increments along three replicate roads per sampling region. At each site, three plots extend from the side of a mountain road into surrounding natural vegetation. The protocol has been successfully used in 18 regions worldwide from 2007 to present. Analyses of one point in time already generated some salient results, and revealed region-specific elevational patterns of native plant species richness, but a globally consistent elevational decline in non-native species richness. Non-native plants were also more abundant directly adjacent to road edges, suggesting that disturbed roadsides serve as a vector for invasions into mountains. From the upcoming analyses of time series, even more exciting results can be expected, especially about range shifts. Implementing the protocol in more mountain regions globally would help to generate a more complete picture of how global change alters species distributions. This would inform conservation policy in mountain ecosystems, where some conservation policies remain poorly implemented.EEA BarilocheFil: Haider, Sylvia. German Centre for Integrative Biodiversity Research; AlemaniaFil: Haider, Sylvia. Martin Luther University. Institute of Biology. Geobotany and Botanical Garden; AlemaniaFil: Lembrechts, Jonas Johan. University of Antwerp. Centre of Excellence Plants and Ecosystems (PLECO); BélgicaFil: McDougall, Keith. Department of Planning, Industry and Environment; AustraliaFil: Pauchard, Aníbal. Universidad de Concepción. Facultad de Ciencias Forestales. Laboratorio de Invasiones Biológicas; ChileFil: Pauchard, Aníbal. Institute of Ecology and Biodiversity (IEB); ChileFil: Alexander, Jake M. Institute of Integrative Biology; SuizaFil: Barros, Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico. Instituto Argentino de Nivología y Glaciología y Ciencias Ambientales (IANIGLA); ArgentinaFil: Cavieres, Lohengrin A. Universidad de Concepción. Facultad de Ciencias Naturales y Oceanográficas. Departamento de Botánica; ChileFil: Cavieres, Lohengrin A. Institute of Ecology and Biodiversity (IEB); ChileFil: Rashid, Irfan. University of Kashmir. Department of Botany; IndiaFil: Rew, Lisa J. Montana State University. Department of Land Resource and Environmental Sciences; Estados UnidosFil: Aleksanyan, Alla. Institute of Botany aft. A.L. Takhtajyan NAS RA. Department of Geobotany and Plant Ecophysiology; ArmeniaFil: Aleksanyan, Alla. Armenian National Agrarian University. Chair of Biology and Biotechnologies; ArmeniaFil: Dimarco, Romina Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. Grupo de Ecología de Poblaciones de Insectos; ArgentinaFil: Dimarco, Romina Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche. Grupo de Ecología de Poblaciones de Insectos; ArgentinaFil: Dimarco, Romina Daniela. University of Houston. Department of Biology and Biochemistry; Estados UnidosFil: Seipel, Tim. Montana State University. Department of Land Resource and Environmental Sciences; Estados Unido
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